Coaxial pipe, tube, and/or hose connection assemblies, particularly those which are used to supply a combination of power-driving or coolant air and lubricating oil to power tools, are known in the art. Exemplary of one type of such known prior art is the fitting or assembly disclosed in U.S. Pat. No. 4,116,475, which issued to Glaser et al. on Sep. 26, 1978. In accordance with such typical or conventional prior art assemblies or fittings, a quick disconnect coaxial coupling socket 17 is disclosed in FIG. 1, for example, as comprising a male pipe threaded fitting 18 within which there is disposed a central or axial tube 24, for mating with a barbed insert 13 of an injection lubricator so as to conduct a suitable lubricant therethrough, and a surrounding annular air passage 19. A three-legged spacer or locator 26 radially supports the axially disposed lubricant tube 24 with respect to the housing 18 and the air passage 19. Other similar embodiments are disclosed in FIGS. 2 and 3.
While the aforenoted patent to Glaser et al. discloses a typical coaxial pipe or tubular assembly or connector for conducting a combination of fluids therethrough, such as, for example, air and a lubricating oil, such an assembly is not directed to an assembly of the type which can readily accommodate coaxially disposed hoses and connections between hose sections. It is frequently required in connection with the use of such hose assemblies upon, for example, cutting tools or the like, to shorten or lengthen or otherwise change or replace the hose sections or assemblies. In addition, in order to minimize operational downtime as much as possible, the exchange or replacement process must be able to be accomplished relatively quickly and easily. These criteria cannot be readily satisfied or met with the assembly of Glaser et al.
While the patent to Glaser et al. characterizes the structural assembly thereof as being of the quick disconnect/connect type, it is seen that the entire coupling socket 17, comprising male pipe threaded fitting 18, must be rotated relative to the fitting 10 in order to mount the coupling socket 17 upon the fitting 10 as a result of the threaded engagement of the male pipe threaded fitting 18 of the coupling socket 17 and the female pipe thread 11 of the fitting 10. This is difficult or awkward to accomplish whereby the assembly may not necessarily be considered a quick connect/disconnect type assembly. In addition, it is noted that due to the axially recessed disposition of the barbed insert 13 within the fitting 10, it is sometimes difficult to properly coaxially align the barbed insert 13 with the grommet 21 in order to provide fluidic communication between tubes 16 and 24 of the fitting 10 and socket 17 because the forward end of the coupling socket 17 is already partially disposed internally of the fitting 10 before the barbed insert 13 can engage the grommet 21.
Another quick disconnect coupling for coaxial fluid lines is disclosed in U.S. Pat. No. 3,820,827 which issued to Boelkins on Jun. 28, 1974. The quick connection/disconnection process of such coupling, however, is relatively complex. More particularly, the coupling assembly comprises a plurality of locking balls 22 and a slidable sleeve 26 mounted upon a valve body member 18 of a socket portion 10. In addition, a sleeve valve 32 is also slidably mounted upon the body member 18. In order to therefore disconnect the plug portion 12 from the socket portion 10, the sleeve valve 32 must first be moved to the left as shown in FIG. 2 whereupon the locking mechanism sleeve 26 can then also be moved to the left so as to release the locking balls 22 and thereby allow the plug portion 12 to be withdrawn from the socket portion 10.
It is also desirable from a manufacturing and assembly point of view that the mating hose sections of the coaxial hose assembly be substantially identical or at least complementary with respect to each other to the greatest possible extent. In addition, from an operational point of view, whereby the various fluids are able to flow through the hose assemblies with maximized flow efficiency and minimized flow resistance, substantially straight-through axial flow paths are desired. Still further, the hose assemblies must be provided with a requisite amount of structural integrity so as to ensure proper and desired mechanical interconnection between the various components of the assembly as well as to ensure the integrity of the fluidic communication between the hose sections. U.S. Pat. No. 4,732,414 which issued to Inaba on Mar. 22, 1988 and U.S. Pat. No. 1,160,703 which issued to Fleming on Nov. 16, 1915 are exemplary of additional coaxial pipe joint assemblies wherein substantially axial flow of both the inner and outer fluids through the assemblies are provided. It is noted, however, that aside from the external joint nut or joint body 1 and 26, respectively, there is no provision of a mechanical joint or interengaging interface between the pipe components because the joint interfaces of both patented assemblies are of the butt-joint type which also require packing 25 and 29, respectively.
A need therefore exists in the art for a quick connect/disconnect coaxial hose assembly which in fact readily enables quick and easy connection and disconnection of the hose assemblies, which is comprised of substantially identical or complementary component parts, which provides substantially axial flow-through of the dual fluids, and which provides good mechanical interconnections so as to ensure both structural and fluidic integrity of the assembly.